This paper presents an observer based dynamic fuzzy logic system （DFLS） scheme for a class of unknown single-input single-output （SISO） nonlinear dynamic systems with external disturbances. The proposed approach d...This paper presents an observer based dynamic fuzzy logic system （DFLS） scheme for a class of unknown single-input single-output （SISO） nonlinear dynamic systems with external disturbances. The proposed approach does not need the availability of the state variables. Within this scheme, the DFLS is employed to identify the unknown nonlinear dynamic system. The control law and parameter adaptation laws of the DFLS are derived based on Lyapunov synthesis approach. The control law is robustfied in H∞ sense to attenuate external disturbance, model uncertainties, and fuzzy approximation errors. It is shown that under appropriate assumptions, it guarantees the boundedness of all the signals in the closed-loop system and the asymptotic convergence to zero of tracking errors. The proposed method is applied to an inverted pendulum system to verify the effectiveness of the proposed algorithms.展开更多
In this article,studies on the multimode excitation problem of waveguides and antennas,the balance/unbalance mech-anism and the balanced feeding techniques in dipole antenna systems are first briefly historically revi...In this article,studies on the multimode excitation problem of waveguides and antennas,the balance/unbalance mech-anism and the balanced feeding techniques in dipole antenna systems are first briefly historically reviewed.In this context,general-ized odd-even mode theory is advanced to quantitatively and approximately describe the mutual coupling effect between a feed line and an antenna.As is mathematically deduced and demonstrated,the modal parity mismatch between the feed line and the antenna should ultimately dominate the unbalance phenomenon in antenna systems.Thus,an elegant,closed-form formula is derived to ap-proximately calculate the“unbalance degree”of a straight dipole off-center fed by a symmetric twin-wire line.Design approaches for the simplest,linear,1-D multimode resonant antennas are introduced.Moreover,the“falling tone excitation”law gauged based on prototype dipoles is revealed and used to develop a mode synthesis design approach for microstrip patch antennas(MPAs)and 2-D sectorial electric dipole antennas.Design examples with distinctive radiation performance are presented and discussed.Finally,possible development trends of multimode resonant antennas are prospected.展开更多
Prosodic control is an important part of speech synthesis system. Prosodic parameters choice right or wrong influences the quality of synthetic speech directly. At present, text to speech system has less effective des...Prosodic control is an important part of speech synthesis system. Prosodic parameters choice right or wrong influences the quality of synthetic speech directly. At present, text to speech system has less effective describe to reflect data relationships in the corpus. A new research approach - data mining technology to discover those relationships by association rules modeling is presented. And a new algorithm for generating association rules of prosodic parameters including pitch parameters and duration parameters from corpus is developed. The output rules improve the correctness of syllable choice in text to speech system.展开更多
This paper proposes an approach to synthesize functional programs of Backus' FP system from input/output instances.Based on a theory of orthogonal expansion of programs,the task of program synthesis is expressed i...This paper proposes an approach to synthesize functional programs of Backus' FP system from input/output instances.Based on a theory of orthogonal expansion of programs,the task of program synthesis is expressed in program equations,and fulfilled by solving them according to the knowledge about the equivalence between programs.Some general knowledge of solving program equations with a number of examples are given in the paper.展开更多
Both enantiomers of fluoxetine were synthesized in five steps from ethyl benzoylacetate (1)using microbial-chemical approach with overall yields of 59% and 62% respectively.(S)-Enan- tiomer can be obtained in >99% ...Both enantiomers of fluoxetine were synthesized in five steps from ethyl benzoylacetate (1)using microbial-chemical approach with overall yields of 59% and 62% respectively.(S)-Enan- tiomer can be obtained in >99% e.e.by resting cell of baker's yeast and the R form was produced in 81 % e.e.by immobilized Geotrichum sp.G 38.展开更多
Fiber materials are promising for electrocatalysis applications due to their structural features including high surface area,controllable chemical compositions,and abundant composite forms.In the past decade,considera...Fiber materials are promising for electrocatalysis applications due to their structural features including high surface area,controllable chemical compositions,and abundant composite forms.In the past decade,considerable research efforts have been devoted to construct advanced fiber materials possessing conductive network(to facilitate efficient electron transport)and large specific surface area(to support massive catalytically active sites)to boost electrocatalysis performance.Herein,we focused on recent advances in fiber-based electrocatalyst with enhanced electrocatalytic activity.Moreover,the synthesis,structure,and properties of fiber materials and their applications in hydrogen evolution reaction,oxygen evolution reaction,oxygen reduction reaction,carbon dioxide reduction reaction,and nitrogen reduction reaction are discussed.Finally,the research challenges and future prospects of fiber materials in electrocatalysis applications are proposed.展开更多
A new and generic synthesis approach has been developed for a range of metal oxide multi-shelled hollow microspheres that are useful in fast and stable battery electrodes and more.
Highly effective catalysts for the oxygen reduction reaction(ORR)and the oxygen evolution reaction(OER)are imperative in renewable technologies.The structural design of multifunctional electrocatalysts remains a huge ...Highly effective catalysts for the oxygen reduction reaction(ORR)and the oxygen evolution reaction(OER)are imperative in renewable technologies.The structural design of multifunctional electrocatalysts remains a huge challenge.Herein,a synthesis approach for hierarchical electrocatalysts is explored for embedding Co_(2)P nanoparticles and Fe–Nx species on hollow porous carbon spheres(Co_(2)P/Fe/NP–HCSs)by the pyrolysis of polystyrene@ZnCo-ZIF(PS@ZnCo-ZIF)composite precursors with the addition of PA and ferrocene.The combination of active species and hollow carbon structures endows Co_(2)P/Fe/NP–HCS electrocatalysts with prominent catalytic abilities for the ORR/OER.Co_(2)P/Fe/NP–HCSs show a positive half-wave potential(0.872 V)for the ORR while achieving a low overpotential(341 mV@10 mA cm^(−2))for the OER.Consequently,a Co_(2)P/Fe/NP–HCS-based Zn–air battery delivers high power density and desirable durability.This study provides a distinct synthetic strategy for preparing practical catalysts for energy conversion equipment.展开更多
文摘This paper presents an observer based dynamic fuzzy logic system （DFLS） scheme for a class of unknown single-input single-output （SISO） nonlinear dynamic systems with external disturbances. The proposed approach does not need the availability of the state variables. Within this scheme, the DFLS is employed to identify the unknown nonlinear dynamic system. The control law and parameter adaptation laws of the DFLS are derived based on Lyapunov synthesis approach. The control law is robustfied in H∞ sense to attenuate external disturbance, model uncertainties, and fuzzy approximation errors. It is shown that under appropriate assumptions, it guarantees the boundedness of all the signals in the closed-loop system and the asymptotic convergence to zero of tracking errors. The proposed method is applied to an inverted pendulum system to verify the effectiveness of the proposed algorithms.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFE0205900)the Key Technologies R&D Program of Jiangsu(Prospective and Key Technologies for Industry)(Grant Nos.BE2022067 and BE2022067-2)。
文摘In this article,studies on the multimode excitation problem of waveguides and antennas,the balance/unbalance mech-anism and the balanced feeding techniques in dipole antenna systems are first briefly historically reviewed.In this context,general-ized odd-even mode theory is advanced to quantitatively and approximately describe the mutual coupling effect between a feed line and an antenna.As is mathematically deduced and demonstrated,the modal parity mismatch between the feed line and the antenna should ultimately dominate the unbalance phenomenon in antenna systems.Thus,an elegant,closed-form formula is derived to ap-proximately calculate the“unbalance degree”of a straight dipole off-center fed by a symmetric twin-wire line.Design approaches for the simplest,linear,1-D multimode resonant antennas are introduced.Moreover,the“falling tone excitation”law gauged based on prototype dipoles is revealed and used to develop a mode synthesis design approach for microstrip patch antennas(MPAs)and 2-D sectorial electric dipole antennas.Design examples with distinctive radiation performance are presented and discussed.Finally,possible development trends of multimode resonant antennas are prospected.
基金This work was supported by the 863 National High Technology Project and the National Natural Science Foundation of China (No. 60275014).
文摘Prosodic control is an important part of speech synthesis system. Prosodic parameters choice right or wrong influences the quality of synthetic speech directly. At present, text to speech system has less effective describe to reflect data relationships in the corpus. A new research approach - data mining technology to discover those relationships by association rules modeling is presented. And a new algorithm for generating association rules of prosodic parameters including pitch parameters and duration parameters from corpus is developed. The output rules improve the correctness of syllable choice in text to speech system.
基金This research is supported by the National Science Foundation and the National Education Committee Foundation for Youths.
文摘This paper proposes an approach to synthesize functional programs of Backus' FP system from input/output instances.Based on a theory of orthogonal expansion of programs,the task of program synthesis is expressed in program equations,and fulfilled by solving them according to the knowledge about the equivalence between programs.Some general knowledge of solving program equations with a number of examples are given in the paper.
文摘Both enantiomers of fluoxetine were synthesized in five steps from ethyl benzoylacetate (1)using microbial-chemical approach with overall yields of 59% and 62% respectively.(S)-Enan- tiomer can be obtained in >99% e.e.by resting cell of baker's yeast and the R form was produced in 81 % e.e.by immobilized Geotrichum sp.G 38.
基金The funding has been received from Fundamental Research Funds for the Central Universities with Grant no.2232021A-02Shanghai Committee of Science and Technology,China with Grant No.21ZR1480000National Natural Science Foundation of China with Grant Nos.52122312,52172291.
文摘Fiber materials are promising for electrocatalysis applications due to their structural features including high surface area,controllable chemical compositions,and abundant composite forms.In the past decade,considerable research efforts have been devoted to construct advanced fiber materials possessing conductive network(to facilitate efficient electron transport)and large specific surface area(to support massive catalytically active sites)to boost electrocatalysis performance.Herein,we focused on recent advances in fiber-based electrocatalyst with enhanced electrocatalytic activity.Moreover,the synthesis,structure,and properties of fiber materials and their applications in hydrogen evolution reaction,oxygen evolution reaction,oxygen reduction reaction,carbon dioxide reduction reaction,and nitrogen reduction reaction are discussed.Finally,the research challenges and future prospects of fiber materials in electrocatalysis applications are proposed.
文摘A new and generic synthesis approach has been developed for a range of metal oxide multi-shelled hollow microspheres that are useful in fast and stable battery electrodes and more.
基金supported by the National Natural Science Foundation of China(No.52072139 and 21964007)the Natural Science Foundation of Hubei Province(No.2019CFB606)+1 种基金the Key Research and Development Program of Hainan Province-Social Development Direction(ZDYF2020204)the Innovation Platform for Academicians of Hainan Province.
文摘Highly effective catalysts for the oxygen reduction reaction(ORR)and the oxygen evolution reaction(OER)are imperative in renewable technologies.The structural design of multifunctional electrocatalysts remains a huge challenge.Herein,a synthesis approach for hierarchical electrocatalysts is explored for embedding Co_(2)P nanoparticles and Fe–Nx species on hollow porous carbon spheres(Co_(2)P/Fe/NP–HCSs)by the pyrolysis of polystyrene@ZnCo-ZIF(PS@ZnCo-ZIF)composite precursors with the addition of PA and ferrocene.The combination of active species and hollow carbon structures endows Co_(2)P/Fe/NP–HCS electrocatalysts with prominent catalytic abilities for the ORR/OER.Co_(2)P/Fe/NP–HCSs show a positive half-wave potential(0.872 V)for the ORR while achieving a low overpotential(341 mV@10 mA cm^(−2))for the OER.Consequently,a Co_(2)P/Fe/NP–HCS-based Zn–air battery delivers high power density and desirable durability.This study provides a distinct synthetic strategy for preparing practical catalysts for energy conversion equipment.
